Pregnant 13 weeks, IgG and IgM rubella come out positive, IgG 101 (+), IgM 1.3 (+), retest after 3 weeks, result the same, is it safe to continue?

Rubella. The presence of igm antibodies suggests, but does not prove, that you have had infection in the "recent" past, but the absence of a rising titer in 3 wks also suggests that the infection was not immediately prior to the first testing. Whether or not you choose to continue your pregnancy is a personal decision, but doubt that these values necessarily predict a negative outcome. Good luck.
Yes. It appears that if the igg titer is considered positive, you have protective level against rubella. The stable igm titers showed that you don't have an active infection.